1. Field of the Invention
In general, the present invention relates to systems and methods for reshaping hair either by adding curls or by removing curls from the hair. More particularly, the present invention relates to systems and methods that utilize the flow of electricity through or near human hair.
2. Background of the Invention
It is well known that different people have different types of hair. Hair comes in different colors and different degrees of fineness. Furthermore, it is easily observed that some people have straight hair while other people have curly or wavy hair.
For a variety of reasons, people with straight hair often endeavor to add body to their hair in the form of waves or curls. Conversely, many people with naturally curly hair endeavor to straighten their hair.
In the prior art, the body of a person's hair can be altered using either physical processes or chemical processes. The physical processes include the application of heat and/or water. Such physical processes include the use of hair dryers, curlers, hair irons and the like. Although such processes can curl or straighten hair, the effect is temporary. The effect is often lost the moment the hair gets wet or is exposed to high humidity conditions. Furthermore, the effects of the hair straightening or curling also fade with time. As such, the physically conditioned hair slowly returns to its natural condition, typically over the course of few hours to a few days depending upon hair type and ambient conditions.
Chemical processes change the body of hair by altering the chemical structure of the hair. Hair is made primarily of keratin proteins. The structure of keratin includes disulfide bridges. When hair is chemically treated, reducing chemicals, such as thioglycolic acid solution, are used to break the disulfide bridges of the hair protein. The hair is shaped as desired. The broken proteins are then reset using a neutralizing agent, such as hydrogen peroxide, that reforms the broken disulfide bridges. Since the chemical structure of the hair has been altered, the effect is called a “permanent” because the hair remains altered and is generally unaffected by subsequent washings.
The scission of the disulfide bridges in the keratin proteins takes place through the following steps. An equilibrium reaction occurs when a reducing agent, such as thioglycolic acid, encounters the disulfide bridge in the keratin structure. This reaction is represented by Equation 1 below where K denotes keratin, S are sulfides, S-S are disulfide bridges, H is hydrogen and R-SH is a reducing agent.K-S-S-K+2R-SHR-S-S-R+2K-SH  Equation (1)This equilibrium actually occurs through a two-step process. The first step is represented by Equation 2. The second step is represented by Equation 3.K-S-S-K+R-SHK-S-S-R+K-SH  Equation (2)K-S-S-R+R-SHR-S-S-R+K-SH  Equation (3)
The reaction is dependent upon the pH of the reducing agent and the time of hair exposure. Since the reducing chemicals being used are often highly alkaline or acidic, the reaction with the hair can be further influenced by the presence of an electrical current. The use of an electrical current in such a manner is exemplified in U.S. Pat. No. 5,743,278 to Ookura, entitled Method And Tool For Hair treatment.
Under conditions where the reactions of the above equations have proceeded enough, but not completely to destroy the hair, a considerable number of the disulfide bridges are severed. When the hair is neutralized, not all of the broken disulfide bridges reform and many disulfide bridges remain broken. This causes the strength of the hair to weaken significantly. Furthermore, the reducing chemicals used to break and reset the disulfide bonds are both caustic and foul smelling. The caustic nature of the chemicals can cause damage to the skin of the scalp and the follicles through which the hair grows. Accordingly, the health of the overall head of hair is further diminished.
A need therefore exists for a system and method that can cleave and repair disulfide bridges in the keratin proteins of hair, thereby creating a permanent change in hair shape without the use of any harsh reducing chemicals. A need further exists for a system and method that leaves fewer disulfide bridges unrepaired after the shape of the hair is altered. In this manner, both the strength of hair and the health of the scalp remain minimally affected. These needs are met by the present invention as described and claimed below.